Apparatus and method for controlling access to network in wireless communication system

ABSTRACT

In a wireless communication system, an apparatus and method for managing an uplink communication between a network and a plurality of terminals is achieved by transmitting a response condition parameter from the network to the plurality of terminals subscribing to a multicast service. The parameter is associated with controlling the uplink communication of the plurality of terminals. The terminal then applies the response control parameter to a predetermined test and responds to the network if the terminal determines that it is qualified to respond to the network in response to a result of the predetermined test. The network evaluates whether the parameter needs to be transmitted to the plurality of terminals and whether the parameter needs to be updated based on at least part of responses received by the network.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Application No.2003-021143, filed on Apr. 3, 2003, the contents of which are herebyincorporated by reference herein in their entirety:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to communicating in a wirelesscommunication system and, more particularly, to an apparatus and methodfor controlling access to a network by mobile terminals.

2. Description of the Related Art

A universal mobile telecommunication system (UMTS) is a European-type,third generation IMT-2000 mobile communication system that has evolvedfrom a European standard known as Global System for Mobilecommunications (GSM). UMTS is intended to provide an improved mobilecommunication service based upon a GSM core network and wideband codedivision multiple access (W-CDMA) wireless connection technology.

In December 1998, a Third Generation Partnership Project (3GPP) wasformed by the ETSI of Europe, the ARIB/TTC of Japan, the T1 of theUnited States, and the TTA of Korea. The 3GPP creates detailedspecifications of UMTS technology. In order to achieve rapid andefficient technical development of the UMTS, five technicalspecification groups (TSG) have been created within the 3GPP forstandardizing the UMTS by considering the independent nature of thenetwork elements and their operations.

Each TSG develops, approves, and manages the standard specificationwithin a related region. Among these groups, the radio access network(RAN) group (TSG-RAN) develops the standards for the functions,requirements, and interface of the UMTS terrestrial radio access network(UTRAN 20), which is a new radio access network for supporting W-CDMAaccess technology in the UMTS.

FIG. 1 illustrates an exemplary basic structure of a general UMTSnetwork. As shown in FIG. 1, the UMTS is roughly divided into a terminalor user equipment (UE) 10, a UTRAN 20, and a core network (CN) 30.

The UTRAN 20 includes one or more radio network sub-systems (RNS) 25.Each RNS 25 includes a radio network controller (RNC) 23 and a pluralityof Node-Bs (base stations) 21 managed by the RNC 23. The RNC 23 handlesthe assignment and management of radio resources and operates as anaccess point with respect to the core network 30.

The Node-Bs 21 receive information sent by the physical layer of theterminal 10 through an uplink, and transmit data to the terminal 10through a downlink. The Node-Bs 21 operate as access points of the UTRAN20 for the terminal 10.

The UTRAN 20 constructs and maintains a radio access bearer (RAB) forcommunication between the terminal 10 and the core network 30. The corenetwork 30 requests end-to-end quality of service (QoS) requirementsfrom the RAB, and the RAB supports the QoS requirements the core network30 has set. Accordingly, by constructing and maintaining the RAB, theUTRAN 20 can satisfy the end-to-end QoS requirements.

The services provided to a specific terminal 10 are roughly divided intothe circuit switched (CS) services and the packet switched (PS)services. For example, a general voice conversation service is a circuitswitched service, while a Web browsing service via an Internetconnection is classified as a packet switched (PS) service.

For supporting circuit switched services, the RNCs 23 are connected tothe MSC 31 of the core network 30 and the MSC 31 is connected to theGMSC 220 that manages the connection with other networks. For supportingpacket switched services, the RNCs 23 are connected to the SGSN 35 andthe GGSN 37 of the core network 30. The SGSN 35 supports the packetcommunications with the RNCs 23 and the GGSN 37 manages the connectionwith other packet switched networks, such as the Internet.

The 3GPP system can provide multimedia broadcast multicast service(MBMS). The 3GPP TSG SA (Service and System Aspect) defines variousnetwork elements and their functions required for supporting MBMSservices. A cell broadcast service provided by the conventional systemis limited to a service in which text type short messages are broadcastto a certain area. The MBMS service is a more advanced service thatmulticasts multimedia data to terminals (UEs) 10 that have subscribed tothe corresponding service in addition to broadcasting multimedia data.An example of MBMS service includes news channels, music channels, moviechannels, etc.

The MBMS service is a downward-dedicated service that provides astreaming or background service to a plurality of terminals 10 by usinga common or dedicated downward channel. The MBMS service is divided intoa broadcast mode and a multicast mode.

The MBMS broadcast mode facilitates transmitting multimedia data toevery user located in a broadcast area, whereas the MBMS multicast modefacilitates transmitting multimedia data to a specific user grouplocated in a multicast area. The broadcast area signifies a broadcastservice available area and the multicast area signifies a multicastservice available area.

Users who desire to receive the MBMS service first receive a serviceannouncement provided by a network. The service announcement providesthe terminal 10 with a list of services to be provided and relatedinformation. In addition, the users must receive a service notificationprovided by the network. The service notification provides the terminal10 with information related to the broadcast data to be transmitted.

If the user intends to receive the multicast mode MBMS service, the usersubscribes to a multicast subscription group. A multicast subscriptiongroup is a group of users who have completed a subscription procedure.Once a user has subscribed to the multicast subscription group, the usercan join a multicast group to receive a specific multicast service. Amulticast group is a group of users that receive a specific multicastservice. Joining a multicast group, also referred to as MBMS multicastactivation, means merging with the multicast group that has users whowish to receive the specific multicast service. Accordingly, the usercan receive the specific multicast data by joining a multicast group(i.e., MBMS multicast activation).

The RNC 23 transfers the MBMS user data to the terminal 10 through thebase station (Node-B) 21 via the user plane of the UTRAN protocol. TheUTRAN 20 transfers the MBMS user data by constructing and maintaining aradio access bearer (RAB) for a call communication between the terminal10 and the core network 30. The MBMS user data is transferred only bydownlink. The MBMS radio bearer facilitates transferring, only to aspecific terminal 10, the user data of a specific MBMS servicetransferred by the core network 30 to the UTRAN 20.

The MBMS radio bearer is divided into a point-to-multipoint type and apoint-to-point type. The UTRAN 20 selects one of the two types of MBMSradio bearers to provide the MBMS service. To select one of the two MBMSradio bearers, the UTRAN 20 should recognize the number of users(terminals 10) of a specific MBMS service existing in one cell.

The UTRAN 20 may count the number of terminals to determine the type ofMBMS radio bearer. The UTRAN 20 informs the terminals that it iscounting the number of terminals when it provides information about theMBMS service via a MBMS common control channel or performs paging for aspecific MBMS service group.

When a terminal 10 receives a service notification of an MBMS serviceindicating that counting is being performed on the correspondingservice, the terminal establishes a connection between an RRC entity ofthe terminal 10 and an RRC entity of the UTRAN 20 by transferring an RRCconnection request message to the UTRAN through an uplink commonchannel. The RRC connection request message informs the UTRAN that theterminal desires to receive the corresponding MBMS service.

By counting the number of terminals 10 that have transferred an RRCconnection request message, the UTRAN 20 can recognize users who desireto receive the specific MBMS service in one cell. The UTRAN 20 then setsup an MBMS radio bearer on the basis of the count.

If the number of users existing in a corresponding cell is smaller thana certain threshold value, the UTRAN 20 sets a point-to-point MBMS radiobearer. If the number of users existing in a corresponding cell isgreater than or equal to a certain threshold value, the UTRAN sets apoint-to-multipoint MBMS radio bearer. However, the conventional pagingmethod through which the UTRAN 20 recognizes the number of terminals 10that desire to receive an MBMS service has the shortcomings.

When the UTRAN 20 performs the MBMS service notification, responsemessages, such as RRC response messages, are sent from terminals 10 thatdesire to receive the MBMS service. The response messages aresimultaneously concentrated at uplink channel, resulting in an increasein interference and load on the uplink. Because the UTRAN 20 performsthe MBMS service notification to the plurality of terminals 10 using theMBMS common control channel and the corresponding terminals 10simultaneously inform the UTRAN 20 that they want to receive thecorresponding MBMS service through the uplink common channel both theinterference and load on the uplink increases.

Because the interference and load increases, an undesirably long periodof time may be required for the terminals 10 to send response messages.For this reason, some terminals may fail to transmit the responsemessage by the time when then UTRAN 20 should set up the MBMS radiobearer.

Once the UTRAN 20 receives a number of response messages from theterminals 10 that is above the threshold for setting up the MBMSpoint-to-multipoint radio bearer up to, the UTRAN does not need toreceive any additional response messages because all requirements forselecting the radio bearer have been met. However, in the conventionalart, even if the UTRAN 20 has already received above a threshold numberof response messages, the UTRAN continues to receive response messagesup until the MBMS radio bearer is set. Therefore, uplink radio resourcesare undesirably wasted.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an uplink communicationmanagement apparatus and method in a mobile communication system capableof alleviating uplink congestion that wastes radio resources during amulticast/broadcast service.

According to a method for managing an uplink communication between anetwork and a plurality of terminals in a wireless communication system,the method comprising the steps of: transmitting a parameter (such asaccess information or response condition) from the network to theplurality of terminals subscribing to, for example, a multicast service.The parameter is associated with controlling the uplink communication ofthe plurality of terminals. The method further comprises applying theparameter to a predetermined test in at least one of the plurality ofterminals and responds to the network if the at least one of theplurality of terminals determines that the at least one of the pluralityof terminals is qualified to respond to the network in response to aresult of the predetermined test. The network then evaluates whether theparameter needs to be transmitted to the plurality of terminals andwhether the parameter needs to be updated based on at least part ofresponses received by the network.

According to one aspect of the invention, preferably, the step ofevaluating whether the parameter needs to be transmitted comprisesdetermining whether a sufficient number of terminals has responded. Ifthe sufficient number of terminals has responded then the network setupsa point-to-multipoint radio bearer for the service. If the sufficientnumber of terminals has not responded then the network setups apoint-to-point radio bearer for the service. Preferably, the step ofevaluating whether the parameter needs to be updated is based on totalresponses from terminals in a cell serviced by the network.

According to another aspect of the invention, the parameter is selectedby the network so that the total number of responses is less than theplurality of terminals subscribing to the service. Also, in response tothe evaluation step, the network updates the parameter from the networkin response to a total number of responses received. Alternatively, thenetwork halts the updating of the parameter when the total number ofresponses satisfies a predetermined condition defined in the network.

According to another embodiment of the present invention, a method formanaging an uplink communication comprises decoding a radio channel tocheck presence of a parameter from the network for use in a particularprocess in the terminal, wherein the parameter is associated withcontrolling the uplink communication from the terminal that issubscribing to an MBMS service provided by the network; receiving theparameter from the radio channel; applying the parameter to apredetermined test in the terminal; determining whether the terminal isqualified to respond to the network in respond to a result of thepredetermined test; responding to the network by sending a responsemessage if the terminal is qualified to respond to the network; andrepeating the above steps if the terminal is not qualified to respond tothe network. Preferably, the step of repeating comprises using anupdated parameter from the network. Also, the step of repeating isperformed for the particular process in the terminal.

According to one aspect of the invention, the parameter from the networkis associated with selectively controlling whether the terminal needs tosend the response message to the network.

According to yet another embodiment of the present invention, a methodfor managing an uplink communication between a network and a pluralityof terminals in a wireless communication system comprises transmitting aparameter from the network to the plurality of terminals subscribing to,for example, a multicast service, wherein the parameter is associatedwith controlling the uplink communication of the plurality of terminals;receiving response signals from a selected group of the plurality ofterminals, wherein the response signals are in response to the parametertransmitted from the network; and evaluating whether the parameter needsto be transmitted to the plurality of terminals and whether theparameter needs to be updated based on at least part of responsesreceived by the network.

According to another embodiment, a wireless communication systemcomprises a plurality of terminals being serviced in a cell; and anetwork for transmitting a parameter to the plurality of terminalssubscribing to a service, wherein the parameter is associated withcontrolling the uplink communication of the plurality of terminals,wherein at least one of the plurality of terminals applying theparameter to a predetermined test, and responding to the network if theat least one of the plurality of terminals determines that the at leastone of the plurality of terminals is qualified to respond to the networkin response to a result of the predetermined test, and the networkevaluating whether the parameter needs to be transmitted to theplurality of terminals and whether the parameter needs to be updatedbased on at least part of responses received by the network.

According to another embodiment of the invention, a wireless terminalfor managing an uplink communication in a wireless communication systemcomprises a decoding means for decoding a radio channel to checkpresence of a parameter from the network for use in a particular processin the terminal, wherein the parameter is associated with controllingthe uplink communication from the terminal that is subscribing to aservice provided by the network; and a processor for receiving theparameter from the radio channel and applying the parameter to apredetermined test in the terminal and determining whether the terminalis qualified to respond to the network in respond to a result of thepredetermined test and responding to the network by sending a responsemessage if the terminal is qualified to respond to the network, whereinif the terminal is not qualified to respond to the network then thedecoding means rechecks the presence of the parameter and the processorapplies the parameter to the predetermined test to determine whether theterminal is qualified to respond to the network. Preferably, theprocessor is adapted to use an updated parameter from the network.

According to one embodiment of the invention, a network for managing anuplink communication in a wireless communication system comprises meansfor transmitting a parameter from the network to the plurality ofterminals subscribing to a service, wherein the parameter is associatedwith controlling the uplink communication of the plurality of terminals;means for receiving response signals from a selected group of theplurality of terminals, wherein the response signals are in response tothe parameter transmitted from the network; and means for evaluatingwhether the parameter needs to be transmitted to the plurality ofterminals and whether the parameter needs to be updated based on atleast part of responses received by the network.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objects and advantages of the invention may be realizedand attained as particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. Features, elements, and aspects of the invention that arereferenced by the same numerals in different figures represent the same,equivalent, or similar features, elements, or aspects in accordance withone or more embodiments.

FIG. 1 illustrates a network structure of a general 3GPP UMTS system.

FIG. 2 illustrates a signal flow chart of an upward response messagedistributing method of a mobile communication system in accordance witha first embodiment of the present invention.

FIG. 3 illustrates a signal flow chart of an upward response messagedistributing method of a mobile communication system in accordance witha second embodiment of the present invention.

FIG. 4 is a flow chart illustrating an access controlling method in anetwork according to an embodiment of the present invention.

FIG. 5 is a flow chart illustrating an access controlling method in anetwork according to another embodiment of the present invention.

FIG. 6 illustrates a block diagram of mobile terminal according to thepreferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a method for reducing congestion of anuplink by controlling how the terminals transmit their response messagesto the network. Although the present invention is illustrated withrespect to a mobile communication system such as UMTS (Universal MobileTelecommunication System) developed by the 3GPP, it may also be appliedto other communication systems operating under similar or differentstandards that utilize different air interfaces, such as CDMA basedsystems. In addition, although the term “UTRAN” is described in theembodiments of the present invention, such term may be substituted with“network” without deviating from the gist of the invention.

In one embodiment of the present invention, a method for reducingcongestion of an uplink controls how the terminals transmit theirresponse messages to the network. When responses are received from someterminals after access information is sent that allows some terminals torespond, it is determined whether subsequent access information needs tobe sent to some terminals based on the received responses.

Access information, also referred to as response condition information,may include various types of uplink control parameters such as terminalgrouping information, response timing information, and responseprobability factors. Initial access information and subsequent accessinformation may be the same or may be different.

For example, access information may pertain to an uplink load conditionor a response condition for the terminal, while the response conditionmay include group identification information or time information.Although methods employing terminal grouping information areillustrated, it can be understood by those skilled in the art that othertypes of access information may also be easily applicable to thetechniques of the present invention.

The methods of the present invention may be performed during an accessprocedure for a particular terminal. The access procedure for aparticular terminal may begin when the terminal correctly receives onedownlink (DL) message and end when the terminal sends one uplink (UL)message. Alternately, the access procedure for a particular terminal maybegin when the terminal correctly receives one downlink (DL) message andend when the terminal recognizes that no more downlink messages for thatparticular procedure will be transmitted.

A paging procedure may be performed for groups of terminals in order todistribute the transmission of response messages. Unlike theconventional art, where the UTRAN simultaneously informs a plurality ofterminals about an MBMS service by using the MBMS common controlchannel, the UTRAN may distributively transfer an MBMS servicenotification to groups of terminals so that response messagetransmissions via the uplink common channel for each terminal group areperformed at different times rather than simultaneously.

In another embodiment of the present invention, a method for minimizingthe waste of radio resources controls the number of response messagestransmitted from the terminals for an MBMS service. Response messagesfrom the terminals, required for setting up an MBMS radio bearer, aredistributively counted.

Distributive counting may be performed by discriminating and samplingthe response messages several times instead of performing the count allat once. The number of sampled response messages may be arbitrarily set.Instead of simultaneously receiving and counting the response messagesfrom terminals, the response messages are initially received and countedfrom only a limited number of terminals. Response messages are receivedand counted from other terminals only if the number of terminalsinitially providing responses does not exceed a threshold value. Thelimited number of terminals may be based on how the terminals aregrouped together.

In order to implement the present invention, terminals that desire toreceive a specific MBMS service are preferably classified into one ormore groups. The classification may be performed by the UTRAN,preferably by a radio network controller (RNC) of the UTRAN.

Group classification may be preformed whenever a user subscribes to theMBMS service. Alternatively, group classification may be preformedwhenever a paging message, or response request message, is transmittedto a terminal by using information about past service access frequencyby each terminal or performance information of each terminal.Classification whenever a user subscribes to the MBMS service ishereafter, referred to as a first classification method. Classificationwhenever a paging message, or response request message, is transmittedto a terminal is hereafter referred to as a second classificationmethod.

Various types of classifications may be applied to the presentinvention. For example, the UTRAN may classify those terminals thatfrequently use a specific service into one group. Alternatively, theUTRAN can randomly classify all the terminals in order to evenlydistribute the terminals into different groups.

When the terminals are classified into one or more groups, the terminalsmust be informed of which group they belong to. The UTRAN transmitsinformation to the terminal indicating to which group it belongs. Thisinformation may be response condition information added to a responserequest message and transmitted.

The response condition information may include identificationinformation of a group that needs to transfer a response message oridentification information of one or more terminals belonging to thegroup. In addition, the response condition information may includeinformation required for determining to which group the terminal havingreceived a response request belongs.

The response condition information indicates which terminal shouldrespond to a response request message and may also include timeinformation indicating when the terminal can transfer a responsemessage. For example, the time information may include frame informationfor transferring a response message, a timer value to be used fortransmission or a transmission limit time of a response message.

In another embodiment of the present invention, a method for countingthe number of terminals in one cell that desire to receive a specificMBMS service transmits a response request message, or paging message, toeach terminal group on the basis of the two types of groupclassifications.

Referring to FIG. 2, a signal flow chart of an uplink response messagedistributing method of a mobile communication system in accordance witha first embodiment of the present invention. The first embodiment isbased on the first group classification method, whereby terminalclassification is performed whenever a user subscribes to, for example,an MBMS service. Although the method is illustrated using two terminals,UE 1 and UE 2, which are assumed to belong to both a first group and asecond group, the method is applicable to any terminal groups containingat least one terminal.

As illustrated in FIG. 2, when a user terminal subscribes to an MBMSservice, the UTRAN informs the user terminals to which group eachterminal belongs by transferring group information to the terminals(step S10). The group information may include a group identifier.

Thereafter, the UTRAN sets up an MBMS radio bearer to provide the MBMSservice. In order to set up the radio bearer, the UTRAN must recognizehow many users desire to receive a specific MBMS service. In order tocount the number of users for the specific service, the UTRAN selectsone group, for example a first group, from previously classifiedterminal groups and configures the response condition information forthe selected first group (step S11).

Once the group is selected and the response condition information isconfigured, the UTRAN transmits a response request message to the firstgroup. As illustrated in FIG. 2, the first group includes UE 1 and UE 2(step S12). The response request message includes the response conditioninformation previously configured in step S11.

When the response request message is transferred from the UTRAN throughan MBMS common control channel, the information that a count is beingperformed for a corresponding MBMS service is received by the terminals,including UE 1 and UE 2, of the first group. The terminals of the firstgroup determine whether to transfer a response message to the UTRAN onthe basis of the response condition information contained in thereceived response request message (step S13).

Each of the terminals, including UE 1 and UE 2, in the first groupchecks whether response condition information is contained in thecorresponding response request message. If there is no responsecondition information in the response request message, the terminalseach transmit a response message to the UTRAN for the specific MBMSservice. If there is response condition information in the responserequest message, each terminal determines whether they can satisfy theresponse condition by using the received response condition information.If a terminal can satisfy the response condition, it transmits aresponse message to the UTRAN. If a terminal cannot satisfy the responsecondition, it does not transfer a response message to the UTRAN.

As illustrated in FIG. 2, if UE 1 qualifies to transmit a responsemessage, then such message is transmitted to the UTRAN. Similarly, if UE2 does not qualify to transmit a response message, no such message istransmitted to the UTRAN. Therefore, UE 1 transmits a response messageto the response request message to the UTRAN (step S14), while UE 2 doesnot. In addition to UE 1, other terminals of the first group maytransmit a response message to the UTRAN as long as they are allowed todo so. The UTRAN determines the number of response messages receivedfrom terminals of the first group, and compares the total number ofreceived responses with a threshold value (step S15).

If the total number of response messages is greater than, or equal to,the threshold value, the UTRAN stops transmission of the responserequest message, sets up point-to-multipoint radio bearer for the MBMSservice, and transfers MBMS data to the terminals in the first group(steps S22 and S23). Therefore, if the number of received responsemessages is greater than, or equal to, the threshold value required forsetting up the MBMS point-to-multipoint radio bearer, the UTRAN does notreceive any additional response messages from the terminals because therequirements for selecting a radio bearer has been achieved.

If the total number of response messages is smaller than the thresholdvalue in step S15, the UTRAN selects another group, for example a secondgroup including UE 1 and UE 2, from the groups to which the responserequest message has not yet been transferred, and configures newresponse condition information for the selected second group (step S16).When the selection of the second group and the configuration of theresponse condition information are completed, the UTRAN transfers aresponse request message to the terminals, including UE 1 and UE 2, ofthe second group (step S17). The response request message preferablyincludes the new response condition information configured in step S16.

Each of the terminals, including UE 1 and UE 2, in the second groupdetermine whether to transmit a response message on the basis of thereceived response condition (step S18). As illustrated in FIG. 2, UE 1cannot transfer a response message, while UE 2 can transfer a responsemessage. Therefore, UE 2 transmits a response message to the responserequest message to the UTRAN (step S19), while UE 1 does not. Otherterminals of the second group may transfer a response message to theUTRAN as they are allowed to do so.

The UTRAN again determines the number of response messages received fromthe terminals of the second group, including the response from UE 2, andadds that number to the number of previously received response messages,including the response from UE 1. The UTRAN compares the total number ofresponses with the threshold value (step S20).

If the total number of responses is greater than, or equal to, thethreshold value, steps S22 and S23 are performed, whereby the UTRANstops transmission of the response request message, sets uppoint-to-multipoint radio bearer for the MBMS service, and transfersMBMS data to the terminals in the first group and second group. If thetotal number of responses is still smaller than the threshold value, theUTRAN either sets up a radio bearer according to the existence of agroup to which the UTRAN can transfer a response request message orselects a new group and configures response condition information (stepS21).

If the total number of responses is still smaller than the thresholdvalue and there are no other groups to which the UTRAN can transmit aresponse request message, the UTRAN determines that a point-to-pointMBMS radio bearer is to be set. If the total number of responses isstill smaller than the threshold value and there is another group towhich the UTRAN can transmit a response request message, the UTRANselects a new group, for example a third group, among those groups towhich the UTRAN has not yet transmitted a response request message. TheUTRAN configures response condition information for the third group andrepeats steps S17 through step S20 until either the total number ofresponses is greater, or equal to, the threshold or there are no othergroups to which the UTRAN can transmit a response request message.

Referring to FIG. 3, a signal flow chart of an uplink response messagedistributing method of a mobile communication system in accordance witha second embodiment of the present invention is illustrated. The secondembodiment is based on the second group classification method, wherebyterminal classification is performed whenever a paging message, orresponse request message, is transmitted to a plurality of terminals.Although the method is illustrated using two terminals, UE 3 and UE 4,which are assumed to belong to both a first group and a second group,the method is applicable to any terminal groups or a cell containing atleast one terminal.

As illustrated in FIG. 3, the UTRAN determines, or forms, a first groupfrom which a response is to be requested in order to count the totalnumber of terminals that desire to receive a specific MBMS service andconfigures response condition information for the group (step S30). Theresponse condition information may be formed by using mobile terminalidentifiers (for example, using last digit of the terminalidentification number), or a number that can be used by the terminal todetermine whether the terminal is a candidate terminal to respond to theUTRAN. Alternatively, any other parameters that can be used todistinguish and thus control access to the network may be used. TheUTRAN forms the group by selecting at least one terminal to which thespecific MBMS service is to be transmitted. As illustrated in FIG. 3,the first group includes, for example, UE 3 and UE 4.

Once the group is formed and the response condition information isconfigured, the UTRAN transmits a first paging message, or responserequest message, to the first group that includes UE 3 and UE 4 (stepS31). The response request message includes the response conditioninformation previously configured in step S30.

Each of the terminals in the first group, including UE 3 and UE 4,determine whether to transfer a response message to the UTRAN on thebasis of the response condition information contained in the receivedresponse request message (step S32). If a terminal can satisfy theresponse condition, it transmits a response message to the UTRAN. If aterminal cannot satisfy the response condition, it does not transfer aresponse message to the UTRAN.

As illustrated in FIG. 3, UE 3 qualifies to transfer a response messagewhile UE 4 does not qualify to transfer a response message. Therefore,UE 3 transmits a response message to the response request message to theUTRAN (step S33), while UE 4 does not. In addition to UE 3, otherterminals of the first group may transmit a response message to theUTRAN as long as they are allowed to do so. The UTRAN determines thenumber of response messages received from terminals of the first group,and compares the total number of received responses with a thresholdvalue (step S34).

If the total number of response messages is greater than, or equal to,the threshold value, the UTRAN stops transmission of the responserequest message, sets up point-to-multipoint radio bearer for the MBMSservice, and transfers MBMS data to the terminals in the first group(steps S41 and S42). Therefore, if the number of received responsemessages is greater than, or equal to, the threshold value required forsetting up the MBMS point-to-multipoint radio bearer, the UTRAN does notreceive any additional response messages from the terminals because therequirements for selecting a radio bearer has been achieved.

If the total number of response messages is smaller than the thresholdvalue in step S34, the UTRAN selects one or more terminals to which noresponse request message has been transmitted, forms a new group, forexample a second group including UE 3 and UE 4, and configures newresponse condition information for the new group (step S36). When thesecond group is formed and the configuration of the response conditioninformation is completed, the UTRAN transfers a response request messageto the second group (step S36). The response request message preferablyincludes the new response condition information configured in step S35.

The terminals, including UE 3 and UE 4, of the second group determinewhether to transmit a response message on the basis of the receivedresponse condition (step S37). As illustrated in FIG. 3, UE 3 cannottransfer a response message, while UE 4 can transfer a response message.Therefore, UE 4 transmits a response message to the response requestmessage to the UTRAN (step S38), while UE 3 does not. Other terminals ofthe second group may transfer a response message to the UTRAN as theyare allowed to do so.

The UTRAN again determines the number of response messages received fromthe terminals of the second group, including the response from UE 4, andadds that number to the number of previously received response messages,including the response from UE 3. The UTRAN compares the total number ofresponses with the threshold value (step S39).

If the total number of responses is greater than, or equal to, thethreshold value, steps S41 and S42 are performed, whereby the UTRANstops transmission of the response request message, sets uppoint-to-multipoint radio bearer for the MBMS service, and transfersMBMS data to the terminals in the first group and new group. If thetotal number of responses is still smaller than the threshold value, theUTRAN either sets up a radio bearer according to the existence of agroup to which the UTRAN can transfer a response request message ordetermines a new group and configures response condition information(step S40).

If the total number of responses is still smaller than the thresholdvalue and there are no other terminals to which the UTRAN can transmit aresponse request message, the UTRAN determines that a point-to-pointMBMS radio bearer is to be set. If the total number of responses isstill smaller than the threshold value and there is at least one otherterminal to which the UTRAN can transmit a response request message, theUTRAN forms a new group, for example a third group, from terminals towhich the UTRAN has not yet transmitted a response request message. TheUTRAN configures response condition information for the third group andrepeats steps S36 through S39 until either the total number of responsesis greater than, or equal to, the threshold or there are no otherterminals to which the UTRAN can transmit a response request message.

Meanwhile, if the total number of the added response messages is smallerthan the threshold value, and there are no more groups to receive theresponse request message, the UTRAN selects a new group from the groupsthat have not yet received a response request message. The UTRANconfigures response condition information for the selected new group,and then the step S36 is performed again (step S40). Thereafter, theUTRAN sets up a radio bearer determined in step S40, and transfers MBMSdata to the terminals through the radio bearer (steps S41 and S42).

Each terminal determines whether to transmit a response message afterreceiving the response condition information. The following equation (1)shows an example of response condition information:

(1) (UE Id mod M)=R, wherein ‘mod’ signifies a UE Id/M calculation.

In equation (1), ‘UE Id’ indicates a terminal identifier used foridentifying a specific terminal. The terminal identifier may include anIMSI (Internal Mobile Subscriber Identity), a TMSI (Temporary MobileSubscriber Identity), or an RNTI (Radio Network Temporary Identity). Thevalue ‘M’ indicates the maximum number of response messagestransmittable by the UTRAN, for example a number corresponding to thetotal number of groups. There are two types of ‘R’ values; an ‘Rn’ valuethat the UTRAN transfers and an ‘Ru’ value that the terminal calculates.

The UTRAN can add one ‘M’ and one or more ‘Rn’s in the response requestmessage as response condition information for receiving a specific MBMSservice. The terminals obtain the values ‘M’ and ‘Rn’ from the receivedresponse request message. The response request messages that arecontinuously repeated for the same MBMS message have the same ‘M’ butmay have different ‘Rn’s. Obtaining the values ‘M’ and ‘Rn’ from theresponse condition information included in the response request messagecan determine whether a terminal transfers a response message.

After the terminals calculate their ‘Ru’ value according to equation (1)by using the obtained value ‘M’ and their own ‘UE Id’, the calculated‘Ru’ value is compared with one or more ‘Rn’s values received from theUTRAN. If an ‘Rn’ value exists that equals the ‘Ru’ value, the responsecondition information is satisfied and the terminal transmits a responsemessage to the UTRAN. If there is no Rn value that equals the Ru value,the terminal does not satisfy the response condition and no responsemessage is sent to the UTRAN.

For example, if the UE Id is ‘8’ and M=4 and Rn=0 is received from theUTRAN, the remaining portions of equation (1) is ‘0’. Therefore, the‘Ru’ value of the terminal is ‘0’. Since Rn=Ru, the correspondingterminal transmits a response message to the UTRAN.

In addition, the number of response messages can be controlled bycontrolling the Rn value. The UTRAN can control the Rn value such thatthe number of response messages to be sampled is set.

For example, the UTRAN may set the response condition information to M=4and Rn=0,1 in a first transmitted response request message and may setthe response condition information to M=4 and Rn=3 in a secondtransmitted response request message. The terminals satisfying theresponse condition information included in the first response requestmessage corresponds to a first group and the terminals satisfying theresponse condition information included in the second response requestmessage corresponds to a second group. The terminals belonging to thefirst group would most likely transfer more response messages than theterminals belonging to the second group because the number of terminalshaving Rn=0 or 1 would be greater than the number of terminals havingRn=3.

Alternately, the UTRAN may set the response condition information as M=4and Rn=3 in the first transmitted response request message and set theresponse condition information as M=4 and Rn=0,2 in the secondtransmitted response request message. The total number of responsemessages transmitted by terminals belonging to the second group wouldmost likely be greater than the total number of response messagestransmitted by terminals belonging to the first group. Therefore, theUTRAN has not yet received enough response messages from the terminalsand the uplink can accommodate more response messages from additionalterminals. The UTRAN then controls the Rn value to suitably control thenumber of response messages.

FIG. 4 is a flow chart illustrating an access control by a network (forexample, UTRAN) according to an embodiment of the present invention. Thefirst and second embodiments of the present invention preferably havethe same operations except for the terminal group classification method(S10 in FIG. 2).

As illustrated in FIG. 4, the UTRAN classifies a plurality of terminalsthat are to receive MBMS service into at least one or more terminalgroups (step S40). The UTRAN then selects one of the terminal groups,transfers common information such as response request messages thereto,and receives response messages from the corresponding terminal groups(steps S41 and S42).

The UTRAN forms an accumulated count of the number of received responsemessages and compares the accumulated response message count with athreshold value (step S43 and S44). If the accumulative count is greaterthan, or equal to, the threshold value, the UTRAN sets apoint-to-multipoint radio bearer (step S45). If the accumulative countis smaller than the threshold value, the UTRAN checks whether there areany additional terminal groups to be selected (step S46).

If there is at least one other terminal group to be selected, the UTRANselects a new terminal group and repeats steps S41 through step S44. Ifthere is no additional terminal group to be selected, the UTRAN sets upa point-to-point MBMS radio bearer (step S48).

Through the above process, the UTRAN can recognize whether terminalsexist in a specific group, or recognize the number of terminals thatexist in a specific group, in order to set up the MBMS radio bearer. Inthe present invention, the existence of terminals in a specific group orthe number of terminals that exist in a specific group for setting upthe MBMS radio bearer is recognized when response messages are receivedfrom terminal groups. Therefore, uplink signal congestion can beminimized and, specifically, transmission of unnecessary responsemessages from the terminals can be prevented.

The message transfer method in a mobile communication system of thepresent invention has several advantages.

Unlike the conventional art, in which response messages are concentratedto the MBMS common control channel, the response messages from theterminals can be effectively dispersed because the paging message isdistributively transferred in accordance with terminal groups.Therefore, uplink signal congestion can be minimized because the MBMSservice notification is not made simultaneously to a plurality ofterminals, but rather made distributively according to terminal groupssuch that different transmission time points are set for transferringthe response messages from the terminals through the uplink commonchannel.

Furthermore, the total number of response messages from the terminalscan be controlled. Response messages are not simultaneously receivedfrom numerous terminals and then counted, but rather received first fromthe terminals of a certain group. If the number of response messagesfrom the first terminal group is greater than, or equal to, a thresholdvalue, no more response messages need be received from other terminalgroups. Because the number of response messages transmitted by theterminals is controlled, undesirable waste of radio resources can bereduced in providing MBMS services.

FIG. 5 is a flow chart illustrating an access controlling method in anetwork according to another embodiment of the present invention.

Referring to FIG. 5, the UTRAN selects an initial parameter (forexample, response condition information) in step S50 and transmits suchparameter to one or more terminals subscribing to a particular MBMSservice, such as a news channel (step S51). The UTRAN then receivesresponses from one or more terminals that qualifies to respond inresponse to the initial parameter (step S52).

The UTRAN forms an accumulated count of the number of received responsesand compares the accumulated response message count with a thresholdvalue (step S54). If the accumulative count is greater than, or equalto, the threshold value, the UTRAN sets a point-to-multipoint radiobearer (step S56). If the accumulative count is smaller than thethreshold value, the UTRAN checks whether there is a need to continuecounting the terminals to decide point-to-point or point-to-multipointtransmission (step S55).

If there is a need for continued counting, the UTRAN updates (orsometimes uses the same parameter) the parameter and repeats steps S51through step S54. If there is no need for continue counting, the UTRANsets up a point-to-point MBMS radio bearer (step S57).

Through the above process and device, the UTRAN controls the uplinkcongestion caused by all terminals that subscribe to a particularservice in a cell from responding to the UTRAN. By controlling theselection or sampling of a subset of such terminals for setting up anMBMS radio bearer, the UTRAN minimizes the uplink traffic congestion.Such selective response control of the terminals may be carried out bytransmitting a parameter from the UTRAN which will be used by eachterminal in a group (for example, subscribing to a particular MBMSservice) to determine whether such terminal qualifies to respond to theresponse request message. If the responses from the terminals areinsufficient (for example, the responses are below a certain thresholdvalue) then the UTRAN decides whether to update the parameter and alsowhether to retransmit such parameter to the terminals in the group.Because the number of response messages transmitted by the terminals iscontrolled, undesirable waste of radio resources can be reduced inproviding MBMS services.

FIG. 6 illustrates a block diagram of mobile terminal according to thepreferred embodiment of the present invention. Both the mobile stationand the network system may utilize the present invention. Referring toFIG. 9, the mobile station 700 comprises a processor (or digital signalprocessor) 710, RF module 735, power management module 705, antenna 740,battery 755, display 715, keypad 720, memory 730, SIM card 725 (whichmay be optional), speaker 745 and microphone 750.

A user enters instructional information, such as a telephone number, forexample, by pushing the buttons of a keypad 720 or by voice activationusing the microphone 750. The microprocessor 710 receives and processesthe instructional information to perform the appropriate function, suchas to dial the telephone number. Operational data may be retrieved fromthe Subscriber Identity Module (SIM) card 725 or the memory module 730to perform the function. Furthermore, the processor 710 may display theinstructional and operational information on the display 715 for theuser's reference and convenience.

The processor 710 issues instructional information to the RF section735, to initiate communication, for example, transmit radio signalscomprising voice communication data. The RF section 735 comprises areceiver and a transmitter to receive and transmit radio signals. Anantenna 740 facilitates the transmission and reception of radio signals.Upon receiving radio signals, the RF module 735 may forward and convertthe signals to baseband frequency for processing by the processor 710.The processed signals would be transformed into audible or readableinformation outputted via the speaker 745, for example.

It will be apparent to one skilled in the art that the preferredembodiments of the present invention can be readily implemented using,for example, the processor 710 or other data or digital processingdevice, either alone or in combination with external support logic.

Although the present invention is described in the context of mobilecommunication, the present invention may also be used in any wirelesscommunication systems using mobile devices, such as PDAs and laptopcomputers equipped with wireless communication capabilities. Moreover,the use of certain terms to describe the present invention should notlimit the scope of the present invention to certain type of wirelesscommunication system, such as UMTS. The present invention is alsoapplicable to other wireless communication systems using different airinterfaces and/or physical layers, for example, TDMA, CDMA, FDMA, WCDMA,etc.

The preferred embodiments may be implemented as a method, apparatus orarticle of manufacture using standard programming and/or engineeringtechniques to produce software, firmware, hardware, or any combinationthereof. The term “article of manufacture” as used herein refers to codeor logic implemented in hardware logic (e.g., an integrated circuitchip, Field Programmable Gate Array (FPGA), Application SpecificIntegrated Circuit (ASIC), etc.) or a computer readable medium (e.g.,magnetic storage medium (e.g., hard disk drives, floppy disks, tape,etc.), optical storage (CD-ROMs, optical disks, etc.), volatile andnon-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs,SRAMs, firmware, programmable logic, etc.). Code in the computerreadable medium is accessed and executed by a processor. The code inwhich preferred embodiments are implemented may further be accessiblethrough a transmission media or from a file server over a network. Insuch cases, the article of manufacture in which the code is implementedmay comprise a transmission media, such as a network transmission line,wireless transmission media, signals propagating through space, radiowaves, infrared signals, etc. Of course, those skilled in the art willrecognize that many modifications may be made to this configurationwithout departing from the scope of the present invention, and that thearticle of manufacture may comprise any information bearing medium knownin the art. The logic implementation shown in the figures describedspecific operations as occurring in a particular order. In alternativeimplementations, certain of the logic operations may be performed in adifferent order, modified or removed and still implement preferredembodiments of the present invention. Moreover, steps may be added tothe above described logic and still conform to implementations of theinvention.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the present invention. The presentteachings can be readily applied to other types of methods and systems.The description of the present invention is intended to be illustrative,and not to limit the scope of the claims. Many alternatives,modifications, and variations will be apparent to those skilled in theart. In the claims, means-plus-function clauses are intended to coverthe structure described herein as performing the recited function andnot only structural equivalents but also equivalent structures.

1-45. (canceled)
 46. A method of controlling access to a network in awireless communication system, the method performed by a terminal andcomprising: receiving response condition information from the networkvia a common control channel, wherein the response condition informationis for a plurality of terminals that subscribed to a service andincludes one or more response probability factors; determining whetherto transmit a response message to the network on the basis of thereceived response condition information; and transmitting the responsemessage to the network if the terminal is qualified to respond to thenetwork.
 47. The method of claim 46, wherein the service is a MultimediaMulticast/Broadcast Service (MBMS) service.
 48. The method of claim 46,wherein the response message is used to count a number of terminals thatrespond to the network from among the plurality of terminals.
 49. Themethod of claim 46, wherein the plurality of terminals are positioned inone cell.
 50. The method of claim 46, wherein the plurality of terminalsare divided into one or more terminal groups.
 51. The method of claim46, wherein the response condition information is an initial parameter.52. The method of claim 46, wherein the response condition informationis associated with selectively controlling whether the terminal needs tosend the response message to the network.
 53. The method of claim 46,wherein the response condition information is associated with a terminalidentifier.
 54. The method of claim 46, wherein determining whether totransmit the response message comprises using the formula: UE id mod M.55. A method of controlling access to a network in a wirelesscommunication system, the method performed by the network andcomprising: configuring response condition information for a pluralityof terminals that subscribed to a service; transmitting the responsecondition information to the plurality of terminals via a common controlchannel, wherein the response condition information includes one or moreresponse probability factors; and receiving one or more responsemessages from the plurality of terminals in response to the transmittedresponse condition information.
 56. The method of claim 55, wherein theresponse condition information is an initial parameter.
 57. The methodof claim 55, wherein the one or more response messages are used to countof a number of terminals.
 58. The method of claim 55, wherein theplurality of terminals are positioned in one cell.
 59. The method ofclaim 55, wherein the plurality of terminals are divided into one ormore terminal groups.
 60. The method of claim 59, wherein the responsecondition information is transmitted to at least one selected terminalgroup among the one or more terminal groups.
 61. The method of claim 55,further comprising: evaluating whether the response conditioninformation needs to be updated based on the received one or moreresponse messages.
 62. The method of claim 61, wherein evaluatingwhether the response condition information needs to be updated is basedon a total of responses from the plurality of terminals in a cellserviced by the network.
 63. The method of claim 55, further comprising:updating the response condition information based on the received one ormore response messages; and transmitting the updated response conditioninformation to the plurality of terminals.
 64. The method of claim 55,further comprising: establishing a point-to-multipoint radio bearer forthe service if a number of responding terminals is greater than or equalto a threshold value.
 65. The method of claim 55, further comprising:establishing a point-to-point radio bearer for the service if a numberof responding terminals is smaller than a threshold value.
 66. Themethod of claim 55, wherein the response condition information isselected by the network such that a total number of responses is lessthan a total number of terminals that subscribed to the service.
 67. Themethod of claim 55, wherein the service is a MultimediaMulticast/Broadcast Service (MBMS) service.